[aeonik]

Datalog has the same capabilities as prolog but allows strings right?

My understanding is that they have very different evaluation strategies, bottom up vs top down. But with laziness and pruning you can still achieve the same goals in datalog with more ergonomics, right?

I think every language should have a prolog or datalog implementation, kind of like regex.

[cmrdporcupine]

In many respects "Datalog" doesn't refer to a single language or implementation or standard. It really just refers to a set of approaches for querying relational datasets using something like Prolog's unification.

By which I mean there are Datalogs that look like Prolog a bit, and others that don't. And things that are "Datalogs" that don't even have their own PL but instead more of an API. And no standard at all.

[usgroup]

No, datalog is a decidable subset of Prolog. That changes everything.